title CopyStr

.386
.model flat, stdcall
.stack 4096

ExitProcess proto, dwExitCode: dword

.data
source byte "This is the source string", 0
target byte sizeof source dup(0)

.code
main proc
	mov esi, 0
	mov ecx, sizeof source

	L1:
		mov al, source[esi]
		mov target[esi], al
		inc esi
		loop L1

	invoke ExitProcess, 0
main endp
end main